Tobias Liaudat

PhD Student

Research Interests

The main motivation of my PhD is to develop a model for Euclid's space mission Point Spread Function (PSF) that will account spatial, spectral and time variations. This model should be able to estimate Euclid's PSF at all the galaxy positions of the satellite's Field of View (FoV) to be able to correct the effect of it on the shear galaxy measurements.

The Euclid satellite, to be launched in 2022, will be able to observe the sky in the optical and infrared, and will be able to map large scale structures and weak lensing distortions out to high redshifts. Weak gravitational lensing is a fundamental tool of cosmology to constrain models. For the mission to be successful the measurements have to be very precise and, therefore, it is vital to have a reliable PSF model.

Master thesis

The Master thesis was done in the CosmoStat laboratory under the supervision of Jérôme Bobin and Christophe Kervazo, where we were focused in the sparse Blind Source Separation (BSS) problem. We developed a method for tackling large scale problems (not able to scan all the observations simultaneously) which is able to parallelise the work by the use of a clever manifold-based matrix aggregation procedure. [Article]